1. Field of the Invention
The present invention relates to the field of LED voltage adjusting techniques, and in particular to a device based on adjusting voltage of negative terminal of the LED light bar imposed on the light bar and drive system for the device.
2. The Related Arts
Liquid crystal display device (LCD) has been widely applied in many electronic devices. Currently, the majority of the LCDs is the back-lit type LCD. The back-lit LCD comprises liquid crystal panel and backlight module. In general, the backlight module can be categorized as direct-lit and edge-lit. The backlight module can provide light source to the liquid crystal panel.
Because LED has the advantages of low power consumption, low heat generation, long life span, small size, fast response and visible light of stable wavelength, LED is suitable for acting as the backlight module for the LCD.
To meet the demands of the ultra-thin LCD-TV, most backlight modules use edge-lit. In LED backlight module, the light bar is the key component. A plurality of LEDs arranged regularly on a stripe base forms a light bar. The known light bars are usually disposed symmetrically on the top and bottom sides or left and right sides of the LCD. However, the light bars can also be disposed on all four sides. In general, a boost converter can be used to drive the light bar. As such, the negative terminal voltage of the light bar can stays at high level.